The extraordinary wave of bad weather that hit the Italian island of Sardinia on Monday night claimed 16 lives and caused huge damage despite police efforts to limit losses in what Prime Minister Enrico Letta described as a "national tragedy."

Torrential rainfall flooded streets, caused rivers to burst their banks, led to building and bridge collapsing, destroyed agricultural lands and livestock. The biggest damage was registered in some areas of northern Sardinia, near the city of Olbia. Winds blew at speeds up to 100 km per hour.

Confirming the high death toll from the flooding, Environment Minister Andrea Orlando told parliament on Tuesday that the amount of rain dumped by the so-called "Cyclone Cleopatra" had not been recorded "in centuries" and had "overwhelmed the island's hydro-geological system."

Among the victims there were two kids aged two and three who were swept away by the water, a police officer whose car plummeted from a collapsing bridge and a family of four people - father, mother and two teenage children - who drowned when their house was flooded. Another person was reported as still missing.

Eyewitnesses described scenes of panic. "I had three cars in front of me. It was raining heavily and suddenly I did not see them anymore. Then a wall of water struck my windshield," a driver was quoted as saying by Corriere della Sera newspaper after he barely escaped being swept away by the water.

A woman said she watched a "huge wave" of water beat down on her home. "We had no electricity or phones and we did not know what was going on .. we saw a huge wave of water reach our house, like an ocean wave, dragging everything away," she was quoted as saying by ANSA news agency.

Another man told La 7 television that he tried his best in vain to save the lives of a father and his two-year-old son who were holding onto a tree branch in a swollen river. But in the chaotic situation, nobody was willing to rescue them. "The two were crying for help before being swept away in front of my eyes. It was terrible, a shame," he said.

Major traffic disruptions delayed flights, trains and ferries throughout the island. More than 2,700 people were forced to temporarily leave their homes to take shelter in public structures such as schools and gyms, according to local authorities.

Several hundred soldiers were deployed to help in the aftermath of the calamity while technicians were monitoring infrastructure safety in their area. Rescue operations, however, were hampered as many roads were impracticable because of the heavy rain and subsequent waves of mud.

The head of Italy's civil protection Franco Gabrielli said after reaching the western island to coordinate relief efforts on Tuesday that the equivalent of six months' worth of rain, or some 440 milliliters of rain, fell in 24 hours.

The storms let up early on Tuesday but were expected to pour down again in the night and continue on Wednesday. Other areas in the south of Italy were also hit by heavy rains. An entire village of Calabria region was evacuated after a nearby river overflew causing big damage.

Letta said after a special meeting with his cabinet ministers that the Italian government was declaring a state of emergency in Sardinia.

"This (the state of emergency) enables us to immediately be able to use rules for more rapid interventions and set aside an initial sum - 20 million euros (27 million U.S. dollars) - for the very first emergencies," he told a press conference in Rome before taking off for Sardinia.

Many citizens complained that the authorities gave them not enough warning of such a major weather event, but according to local experts the disaster in Sardinia especially brought to the forefront the need of greater environmental protection and maintenance.

The probable rise in temperatures could cause more frequent and intense flooding phenomena in a country where more than six million people are exposed to floods, said the President of the National Council of Geologists, Gian Vito Graziano.

"Nothing has changed in years. Despite the alarms raised by everybody, maintenance remains unfinished in Italy, which has become truly alarming," he told Rai state television.

"We continue to say that we do not have the money for maintenance, but the truth is we have to find the necessary resources. Maybe a little reduction of military spending in favor of more maintenance would avoid that we have to count the number of dead people at every heavy rain," the expert stressed.